Mexico's state oil company said Friday it was searching for 10 workers from a Texas-based company who evacuated from a research vessel in the Gulf of Mexico ahead of Tropical Storm Nate.

Petroleos Mexicanos said it has two ships searching in the area where the workers, employed by Houston-based Geokinetics Inc., called for help Thursday afternoon after leaving a vessel known as a liftboat, the Trinity II, on an enclosed life raft.

"We're deeply concerned about the incident in the Gulf of Mexico involving our employees and others who had to abandon a disabled liftboat due to conditions brought about by Tropical Storm Nate," said Geokinetics spokeswoman Brenda Taquino.

Taquino said the company learned Thursday morning that the Trinity II, contracted from Louisiana-based Trinity Liftboat Services LLC, was disabled in the Bay of Campeche because of storm conditions. A liftboat can lower legs to the sea floor and then elevate itself above the water.

On board were four crew members who operate the liftboat, three contractors and three employees of Geokinetics, which specializes in seismic studies for the oil and gas industry. Mexican authorities said the majority were foreigners, though it did not say from which countries.

The captain reported they were abandoning the vessel about midday Thursday, and a ship several kilometres away also reported seeing the crew enter the life raft.

But there has been no communication since.

Taquino said the life raft is a sealed capsule that contains enough food and water to last for several days, but there is no way to communicate with it.

Tropical Storm Nate was drifting slowly west-southwestward over the southern Gulf Friday with maximum sustained winds of near 80 km/h, according to the U.S. National Hurricane Center in Miami. It was centred about 241 kilometres west of Campeche. Forecasters said it was expected to resume a northwestward path and hit Mexico's Gulf Coast Sunday or Monday.

Maria, Katia on the move

Tropical Storm Maria, meanwhile, could reach the Lesser Antilles in the Atlantic by Friday night and rain from what had been Tropical Storm Lee continued inundating a wide portion of Pennsylvania and other northeastern states, leaving at least seven dead.

Maria's maximum sustained winds Friday were near 75 km/h, with some slight strengthening possible, according to the U.S. National Hurricane Center in Miami. It was centered about 345 kilometres east-southeast of the French Caribbean island of Guadeloupe and moving northwest at about 26 km/h.

A tropical storm warning was in effect for a host of islands: Antigua, Anguilla, Barbuda, Montserrat, Nevis, St. Kitts, the British Virgin Islands, the U.S. Virgin Islands, Guadeloupe, St. Maartin, Saba and St. Eustatius.

A tropical storm watch was in effect for St. Barthelemy, St. Marteen, Martinique, Dominica, and Puerto Rico including Vieques and Culebra.

On its current forecast track, Maria's centre would reach the Leeward Islands early Saturday and be near the Virgin Islands by Saturday night, the hurricane centre said.

Also in the Atlantic, Hurricane Katia was moving northeast over open water after passing between the U.S. and Bermuda.

Despite not hitting land, the hurricane centre said large swells generated by the Category 1 storm will continue affecting the Eastern Seaboard and Bermuda.

Katia is already bringing "large waves" to the Atlantic coast of Nova Scotia, forecasters say, even though the storm is far from land.

The storm is still about 400 kilometres from Halifax and will track "well south" of the Atlantic provinces, the Canadian Hurricane Centre said Friday night. 

Katia had maximum sustained winds of 140 km/h. The long-term forecast indicated it could reach Scotland as a storm on Monday.